PDA

View Full Version : Me or the Glass?


LiquidOps
Jul-27-2006, 12:26 PM
My images come out way too soft... i can't tell if it's me or the glass?

Body: 30D
Lense: Tamron 28-75 f/2.8 (the one everyone praises so much)

Here's the large -

http://WanderingThroughLife.smugmug.com/photos/84363705-L.jpg

Link to the original - http://WanderingThroughLife.smugmug.com/photos/84363705-O.jpg

and here's the exif link EXIF (http://wanderingthroughlife.smugmug.com/photos/newexif.mg?ImageID=84363705)

HELP!!!

gus
Jul-27-2006, 12:31 PM
My images come out way too soft... i can't tell if it's me or the glass?

Body: 30D
Lense: Tamron 28-75 f/2.8 (the one everyone praises so much)

Here's the large -



Link to the original - http://WanderingThroughLife.smugmug.com/photos/84363705-O.jpg

and here's the exif link EXIF (http://wanderingthroughlife.smugmug.com/photos/newexif.mg?ImageID=84363705)

HELP!!!
Was it tripod or handheld ?

LiquidOps
Jul-27-2006, 12:32 PM
Was it tripod or handheld ?

Tripod

JimM
Jul-27-2006, 12:32 PM
Your shutter speed is too slow to be hand-holding the camera. 1/20 sec is not hand holdable to be sharp. Did you use a tripod?

LiquidOps
Jul-27-2006, 12:33 PM
Your shutter speed is too slow to be hand-holding the camera. 1/20 sec is not hand holdable to be sharp. Did you use a tripod?

Yup

JimM
Jul-27-2006, 12:34 PM
How did you release the shutter? If you did not remotely release it, I bet the camera still moved a little (even on the tripod).

LiquidOps
Jul-27-2006, 12:37 PM
How did you release the shutter? If you did not remotely release it, I bet the camera still moved a little (even on the tripod).

makes sense....

let me upload exhibit B

LiquidOps
Jul-27-2006, 12:41 PM
makes sense....

let me upload exhibit B

Large:
http://WanderingThroughLife.smugmug.com/photos/84366253-L.jpg

Origina Link - http://WanderingThroughLife.smugmug.com/photos/84366253-O.jpg

Exif: EXIF Link (http://wanderingthroughlife.smugmug.com/photos/newexif.mg?ImageID=84366253)

straight from camera

Steven

LiquidOps
Jul-27-2006, 12:42 PM
There almost appears to be a double lign down his right arm...

Seefutlung
Jul-27-2006, 12:54 PM
Dude, the EXIF states that you were shooting at 1/20 of a sec at 75mm ... if you weren't using a tripod you are way over the Rule of Thumb. Rule of Thumb is shutter no less than the recipocal of the focal length ... so at 75mm your shutter speed should be no less than 1/125 of a sec. Anything less of Rule of Thumb and you run into "camera shake" problems. Camera shake can be reduced or eliminated by:
1) using a shutter speed greater than the recipocal of the length of the lens;
2) using a tripod w/ remote shutter release;
3) using an IS lens (IS is only good for two or three stops)
4) trainign yourslf to handhold at below Rule of Thumb shutter speeds (no coffee allowed

Remember that most lenses get softer at the extreme aperatures ... at both wide open and closed down the light has to do a lot of bending to focus on the sensor ... and you were at F22, which is at the extreme end or very near the extreme end.

These are all things to be aware when expecting razor sharp photos. If this was a RAW pix, all RAW pixs require some sharpening in a PP program as they come out of the camera with absolutely no processing whatsoever (nada).

And finally, look at your lens and make sure that the AF switch is in the "on" position.

Man that lake looks familar ... where were the ducks.

Good Luck

Seefutlung
Jul-27-2006, 12:58 PM
Oh, one more thing ... when the little rectangles flashes "Red" does not mean that the shot is in focus ... there is a "Green" light on the lower right of the viewfinder that flashes for focus. You may be releasing the shutter too soon. Red means that's the focus rectangle being used for focus.

LiquidOps
Jul-27-2006, 01:02 PM
Oh, one more thing ... when the little rectangles flashes "Red" does not mean that the shot is in focus ... there is a "Green" light on the lower right of the viewfinder that flashes for focus. You may be releasing the shutter too soon. Red means that's the focus rectangle being used for focus.

I don't shoot until i hear the Focus Confirmation Beep

Seefutlung
Jul-27-2006, 01:11 PM
I don't shoot until i hear the Focus Confirmation Beep

Well, if you're not doing anything I mentioned in my postings ... and if the images from other lenses are sharp ... then it gotta be your lens.

Are images from other lenses sharp? Is every image from the Tammy soft? Is every image at a certain focal length soft? Have you performed a do-it-yourself focus test?

LiquidOps
Jul-27-2006, 01:13 PM
Well, if you're not doing anything I mentioned in my postings ... and if the images from other lenses are sharp ... then it gotta be your lens.

Are images from other lenses sharp? Is every image from the Tammy soft? Is every image at a certain focal length soft? Have you performed a do-it-yourself focus test?

i haven't done a serious test... but i shot with the Canon L 70-200 f/2.8 IS USM (borrowed from a friend) and everything was sharp....

everything from the Tamron seems to come out soft... and most with a double line around it, like the last (exhibit B) picture I posted...

Thanks for your help...

and the lake is in Irvine :)

DJ-S1
Jul-27-2006, 01:25 PM
Caveat: I'm no expert!

My copy seems to be pretty sharp to me. It definitely is softer at f/2.8, stepping up a few stops makes a big difference. I haven't had much luck shooting any of my lenses at very small apertures like f/22. Maybe you could post some shots at f/8 for comparison if you get a chance.

On the crowd shot, where was the focus lock? In the software that comes with the camera (can't remember the name right now) there's an option to show the AF spots that lit. I'd be curious to see what it thinks was in focus. Some things in that shot definitely look weird, like the check pattern on his shorts. I don't know if that lens distortion or CA or what?

It is possible that you have a bad copy. Or it could be your body itself. You could check with other lenses wide open to rule that out... guess you did that...

SpeshulEd
Jul-27-2006, 06:08 PM
my guess is that since both images were extreme apertures thats why they're soft. With my sigma lenses everything is soft on the extremes, but if I set them around f/8 or so, everything is good.

I think it'd definitely be worth it to do some test photos with a tripod. Hit a bunch of different f stops aiming at the same thing and see what happens. I'd also try to get your shutter as fast as it'd go, that way you know its not from bumping anything and your lens is just soft.

Pezpix
Jul-27-2006, 06:18 PM
Thought that lake looked familiar :thumb

Bro, maybe I missed it, but do you have any filters in front of your glass either? Sometimes they can be the culprit as well.

Could be in need of calibration if nothing else.

Seefutlung
Jul-27-2006, 06:33 PM
Really sounds like a bum lens ... if another lenses is sharp .... then ... I'd do a quick, do-it-at-home sharpness test on a garage door or equal ... tripod and self timer.

Most peoples lack of sharpness is user error ... but I looks as if you've covered all the bases ... only leaves the lens as a suspect. Focus manually and with auto see if there's a difference.

ziggy53
Jul-27-2006, 06:49 PM
Large:
http://WanderingThroughLife.smugmug.com/photos/84366253-L.jpg

Origina Link - http://WanderingThroughLife.smugmug.com/photos/84366253-O.jpg

Exif: EXIF Link (http://wanderingthroughlife.smugmug.com/photos/newexif.mg?ImageID=84366253)

straight from camera

Steven

Steven,

The first image shows evidence of atmospheric haze. See how the background contrast gets softer the further away it gets. That plus the potential bounce from the shutter at the speed used could explain the results.

The second shot above is more interesting. The exposure shows 1/1000th at f2.8 (wide open). DOF is very shallow. The light is very "harsh" (I did that just for Shay :D).

I processed with moderate USM, and took a crop from what I believe is prime focus.

It looks to be sharp on the "left" arm and left nipple, so slightly back focused from where I would have recommended for the shot.

ziggy53
Jul-27-2006, 06:54 PM
I also pulled a crop a little lower, and sampling the area around the waistband of the shorts, I found pixels at 255,254,255 which implies overexposure.

Ideally, you should have stopped down a bit and used some fill flash at maybe -2 FEC.

That said, I see some "blooming" which could be from internal reflections or possibly a filter.

Do you use a filter on this lens? (edit, I just saw Pez already asked.)

LiquidOps
Jul-27-2006, 06:58 PM
no filter... just the lens

are you leaning more towards user error (i'd be extatic with that) or the lens?

I'd prefer it be me and not the lens....

ziggy53
Jul-27-2006, 08:23 PM
no filter... just the lens

are you leaning more towards user error (i'd be extatic with that) or the lens?

I'd prefer it be me and not the lens....
Neither you nor the lens are off the hook yet. We have to check the lens for internal reflections.

A fairly good test is a single street light, or a single porch light, at night, probably about a half-city-block away. Put the light a little off center in the frame.

Try a lot of different exposure values. Settle on whatever gives some real definition to the light, you don't want it completely blown out.

Move the light from center little by little, you may even see some "echoes" of the light through the viewfinder. A little amount of reflection is fairly normal. If you see too much of a distinct secondary image anywhere in the frame, it may be a problem.

See how the situation changes with aperture. Wide open should be worst, with any problem rapidly diminishing as the aperture closes down. Reflections far off axis should be the most affected, and reflections just barely off axis may be normal, even at middle aperture.

Once you see how this lens performs, try a similar test with another lens for a comparison.

Good luck.

ziggy53

David_S85
Jul-27-2006, 08:38 PM
Do not use f/2.8. Ever.

Anything less than f/5.0 just isn't going to turn out as sharp as you would like it to be, even in the middle of the frame. It's a very nice lens for the price, and so much sharper and contrastier (that isn't a word) than the kit lens, but it just isn't up to par with the 24-70 L that Canon makes.

LiquidOps
Jul-27-2006, 09:14 PM
Do not use f/2.8. Ever.

Anything less than f/5.0 just isn't going to turn out as sharp as you would like it to be, even in the middle of the frame. It's a very nice lens for the price, and so much sharper and contrastier (that isn't a word) than the kit lens, but it just isn't up to par with the 24-70 L that Canon makes.

Well thanks....

i'm very sad now... the reviews i read kind of leaned towards otherwise...

so i guess it is the lens as well as me...

now i gotta find me a new portrait lens...

bah :( :cry

David_S85
Jul-27-2006, 09:51 PM
Hmmm. Separate your subject from the background more and get closer to the subject at the longer focal setting. Try using f/4.5. And portraits shouldn't always need be tack sharp.

Try a 1.4 tele adaptor. My 1.4x Tamron works pretty well on the 28-75, but only at the 75mm setting. You'll be in the 160's, but the focal might just work right to get you the shallower DOF and distance.

There aren't many lenses that are sharp over the range of apertures. Sweet spots are almost always in the middle somewhere. At higher settings (f/18+) you'll begin to notice another drop off in sharpness, even in stellar glass.

The 28-75 is still one of the all-time best walk around lenses made.

Manfr3d
Jul-28-2006, 10:23 AM
Your shutter speed is too slow to be hand-holding the camera. 1/20 sec is not hand holdable to be sharp. Did you use a tripod?

In the 2s to 1/30s mirror flip up vibration is at its worst.
With a flimsy tripod you can sill ruin the sharpness
because of that. Mirror Lockup can help you here.
Or a shutter speed outside this interval.

Steve Cavigliano
Jul-28-2006, 04:06 PM
LO,
It may be both (the lens and yourself). It's hard to tell from these shots. First of all, this lens is nowhere near as soft wide open or near wide open as David lets on. It is softer at F2.8 than at F4 for sure. But F2.8 shots sharpen nicely. Sort of like 70-200 F2.8 shots. It also seems sharper mid-zoom, away from the extremes. IMO and experience, this lens is useable at all apertures and focal lengths :thumb

Your landscape shot is fine for the flat light and settings it was taken under. 2 minutes in post and it is as good as it's probably going to get. Unless you want to really alter it by dropping in some blue sky. May I ask why you chose F22? You will see some difraction issues @ apertures of F16 or higher. This can also cause the image to look less crisp.

http://freezeframephotography.smugmug.com/photos/84562220-L.jpg

Other than some over exposed areas, which are going to look soft (and are prone to CA or blooming), and a shallow DOF, I don't see the issue with the 2nd shot :dunno F2.8 will be somewhat softer. Even more so when you over expose. Your DOF when you are that close to your subject will also be shallow.

I agree with Ziggy. When faced with mixed lighting like this you should use a fill to balance it out. I also agree that using a tripod for slow speed shots isn't enough. You should also use a remote release and lock the mirror to minimize the possibility of camera shake.

Anyhow, don't be sad. If it is the lens, then you can get Tamron to fix it. If it is you, we will beat you into submission :rofl Either way, you will be getting good results from this baby soon :D

All you have heard about this lens is true. I have nothing but kudos for it. And yes I shoot it from F2.8-F11. The only issues I ever have with it are due to the idiot behind the viewfinder :rolleyes

Steve